By calling for reintegration rather than integration, the diverse and complex history of human infrastructural works is recognized. The cradles of civilization in Mesopotamia, Egypt, Indus Valley, and Yellow River valley provide a strong precedent. For these civilizations, the river was the infrastructural backbone of life. Each culture was initially defined by a river which provided transportation, irrigation, and fertility. Although human interventions during the initial evolution of civilization were relatively minor compared to contemporary infrastructural systems, the infrastructure of the ancient world was no less integral to human survival and prosperity. For example, use of a river by a fishing boat transforms it into an infrastructural entity through the introduction of a system of production derived from the landscape, and this system of production was part of a much larger network of food provision. The Tigris, Euphrates, Indus, Yellow, and Nile rivers were the physical operative platform for the systems which provided basic services and necessities for each civilization.